A cold and diffuse giant molecular filament in the region of l=41°,b=-1°

Data of ~(12)CO/~(13)CO/C180 J=1→0 emission toward the Galactic plane region of l=35° to 450 and b=-5° to+ 5° are available with the Milky Way Imaging Scroll Painting(MWISP) project.Using the data,we found a giant molecular filament(GMF) around l≈38°~42°,b≈-3.5°~0°,V_(LSR)≈27~40 km s~(-1),named the GMF MWISP G041-01.At a distance of 1.7 kpc,the GMF is about 160 pc long.With a median excitation temperature about 7.5 K and a median column density about10~(21) cm~(-2),this GMF is very cold and very diffuse compared to known GMFs.Using the morphology in the data cube,the GMF is divided into four components among which three show filamentary structure.Masses of the components are 10~3~10~4 M_☉,with a total mass for the whole filament being about 7×10~4 M_☉from the local thermodynamic equilibrium method.~(13)CO cores inside each component are searched.Virial parameters are about 2.5 for these cores and have a power-law index of -0.34 against the mass.The mass fraction of dense cores traced by ~(13)CO to the diffuse clouds traced by ~(12)CO is about 7% for all components of the GMF.We found signatures of possible large scale filament-filament collision in the GMF.